A number of different devices and arrangements intended for dynamic control of running trim of vessels or boats are previously known.
One such previously known arrangement comprises the use of a so-called interceptor member, constituted of a plate or an interceptor member preferably arranged transverse to the bottom of the vessel and arranged thereto. During driving of the vessel, such an interceptor member increases the water pressure acting on the bottom of the hull in front of the interceptor member and, accordingly, changes the running trim of the boat or vessel.
EP 1 075 415 discloses an arrangement for dynamic control of running trim and list of a boat, which boat has a hull with a stern. The disclosed arrangement comprises a T-shaped interceptor member and a T-shaped housing member, actuating means provided in the vicinity of a substantially vertical part of the interceptor member and the housing member, respectively, and a power supply means. The actuating means is arranged for displacing the interceptor member in a generally continuous and linear movement, in a generally vertical direction, between first and second end positions in relation to the housing member. The interceptor member has a first and a second portion, wherein the first portion extends essentially perpendicular from the middle of the entire length of the second portion. The housing member partially encloses the first portion so that the housing member guides the first portion during the linear movement of the interceptor.
According to EP 1 075 415, the actuating means is arranged in the middle of the external edges of the elongated housing member and the interceptor member, i.e. the actuating means is arranged to act symmetrically in the direction of displacement of the interceptor member. This is to avoid jamming of the interceptor member during movement of the interceptor member between the first and second positions.
In the case when a water jet units are used to operate a boat or vessel, the discharge openings, i.e. the outlet nozzles, of such water jet units are normally positioned far down on the stern, for example in the vicinity of the lower edge of the stern. This means that an interceptor arrangement as described in EP 1 075 415 would be difficult to use, since such an arrangement may require that the interceptor unit would have to be positioned such that its centre part will interfere with the components forming part of a waterjet unit.